Two boys from my first marriage who are 16 and 21. 2nd wife and I had a little girl two years ago. I was 44 at the time. We've been trying for another, but wife having issues - hopefully this current pregnancy sticks.
If so, I will be 46 when the last kid is born. I will not lie - the addition of the baby girl when we had been "kid" free for several years was a big shock to the system. The lack of sleep was probably the biggest problem for me. My energy levels are not what they were 20 years ago. My wife and I had issues for the first six months, but we worked through them. Importantly, both of us have recognized that we still need some life/lives of our own - we've been on a week-long vacation by ourselves (thanks to her parents), we give each other time to do stuff outside of the home, there are times when we realize that one of us just needs a break (go watch a game, grab a drink with friends, whatever) and we take turns.
While I have been tired (its gotten much better the past 8 months)at the same time, I find myself a more attentive and caring Dad. I'm really enjoying slowing things down, appreciating the moments, etc. I did not do that very much when I was younger, which I regret. My little girl is awesome and so full of energy and life. She really has reinvigorated my life -it's almost like being young again. I'm looking forward to her having a sibling. The house is just really happy, fun, and feels complete.
No doubt, its not for everyone. I've come to love andappreciate it as an opportunity to add to my life and not view it as a hindrance.